title: EPR parameters of radical ions and polarizability effect.
abstract: The literature data on substituent influence on the g factors, hyperfine coupling (hfc) constants (a) of the EPR signals and the spin densities (ρ) have been analyzed for 25 series of the organic radical cations and radical anions as well as of the transition metal complexes. The g, a, and ρ values were first established to depend not only on the inductive and resonance effects but also on the polarizability of substituents which can be characterized by the σ(α) constants. The polarizability effect is caused by the partial charge on the radical center. This effect consists in an electrostatic attraction between the charge and the dipole moments induced by this charge in the substituents. The polarizability contribution ranges up to 92%.
authors.affiliation: G A Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, Nizhny Novgorod, Russia.
authors.forename: Alexey N
authors.initials: AN
authors.lastname: Egorochkin
authors.forename: Olga V
authors.initials: OV
authors.lastname: Kuznetsova
authors.forename: Nadiya M
authors.initials: NM
authors.lastname: Khamaletdinova
authors.forename: Lada G
authors.initials: LG
authors.lastname: Domratcheva-Lvova
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*
chemical_list: D001555:Benzene Derivatives; D005609:Free Radicals; D007477:Ions; D009942:Organometallic Compounds